Pressure and magnetic key blank for locks



June 2, 1959 D. B. BUCK 2,888,817

PRESSURE AND MAGNETIC KEY BLANK FOR LOCKS Filed Feb. 20. 1956 2 Sheets-Sheet 1 David Buc/f IN V EN TOR.

BY MMLW June 2, 1959 D. B. BUCK 2,888,817

PRESSURE AND MAGNETIC KEY BLANK FOR Locxs Filed Feb. 20. 1956 2 Sheets-Sheet 2 v F/g. 3 i WKK ,02 l- :fk /00 David BQ Buc/f IN V EN TOR.

United States Patent PRESSURE AND MAGNETIC KEY BLANK l FOR LOCKS This invention relates generally to a key blank convertible to a key for opening locks then again convertible to a key blank. The invention relates particularlyy toa novel device for tting into locks that vary through arrange of sizes for quickly and easily opening the lock.

This invention relates more particularly to. a novel magnetic key mechanism adapted to open locks Without the original key. There areseveral hundred diiferent key blanks such as cylinder, oat, bit and double sided which are presently on the market. An objectjof this invention is to reduce the number of necessary key blanks very drastically by providing an eXpansible blank adapted to lit a wide range of lock sizes and lock varietie and to be operative in connection with them.

A further object of this invention and one which is equally as important is to provide a very simple mechanism for opening a lock Without having the key that was'originally made for that particular lock, the mechanism including a hollow deformable casing that houses magnetizable'particles that are preferably in a uent vehicle, as oil, alcohol, water or air so that upon application of pressure to the particles in their vehicle the casing deforms to the necessary size and shape to t the particular lock with its tumblers (when a tumbler type lock is used).

Anotherobject of the invention is to provide` a locksmith with a simple tool with which he can easily make a, correct metal key for any lock without de-coding numbers or original key as a pattern in that the invention provides an expansible casing which is useful for easily reading the tumblers and working parts within the4 lock. The casing, after being expanded by the application of pressure thereinto is made rigid at least temporarily by the application of a magnetic-field in the presence of the magnetizable particles, whereby they, being'ca'ptive iu the casingifolm a solid.

A further object of the invention is to provide a lock key blank which is capable of being reused many times in 'that the configuration of the blank after being altered to t the particular lock with which it is being used, automatically returns to the original shape upon removal of the magnetic eld from the region of the magnetizable particles in the expansible and deformable casing and also the cessation of the application of pres-` surelthereon.

Another object of the invention is to'provide a compact device which functions to take the place of the key blank board together with the blanks thereon normally carried by a locksmith with which to make keys, when the locksmith Wishes merely to open a particular lock.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

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Figure 1 is an elevational view of one embodiment of the invention, portions being shown schematically;

yFigure 2 is a longitudinal sectional view of a cylin-` der lock and a part of the structure in Figure l, showing a key blank after it has been formed to the proper size and shape in order to actuate the lock;

Figure 3 is a fragmentary longitudinal sectional view of a modified form of the invention;

Figure 4 is a transverse view in `enlarged scale and taken on the line 4 4 of Figure 3;

Figure 5 is a longitudinal sectional View of a modication of the invention;

Figure 6 is a transverse sectional view taken on the line 6-6 of Figure 5; and

Figure 7 is a fragmentary plan view of a modification wherein a constrictor is usedy on the expansible casing as would be the case in connection With some locks where it is desired or considered necessary to restrain a portion of the casing.

Lock 10 is shown in section in Figure 2, this lock being of a standard tumbler type. Its function in the drawing is to show that one embodiment of the invention as typified by the key blank and key mechanism 12, is operable in connection with a tumbler type lock. The principles of the invention may be applied to other types of locks. Tumbler lock 10 comprises a casing 14 Ahavingthe customary front face plate 16 thereover.

Casing 14 has a plurality of radial bores 18 formed therein, the outer ends of which "being in communication with bore 20 extending in the casing 14 and accommodating barrel 22 for rotation. The barrel has a series of bores 24 adapted to align with the bore 18 when barrel 22 isy in the locked position. Key slot 26 extends longitudinally into the barrel 22 as is customary, the lower ends of the bores 24 being in communication with key slot 26 along one side thereof. Driver pins v28. are slidably mounted in bores 18, these driver pins being biased constantly towards the barrel 22 by means of springs 30. The driver pins 28 are of the same length while springs 30 are of equal spring rates and constants. Tumbler pins 32 are slidable in the bores 24, moving into the key slot 26 before the barrel 22 is rotated in bore 20. At such position in the rotation against the opposing bias of the springs 30. The key being of proper shape pushes the tumbler pins 3 2 to the precise distance necessary to have the tumbler pins outer surfaces coincide with the surface of bore 20 (Figure 2). In this position of pins the key is rotata- 1 ble with barrel 22 in order to rotate it and unlock Vthe lock.

The locksmith has a customary and usual procedure for making a key from a blank. Since there are such a large num-ber of sizes and makes of locks presently available, the locksmith'must maintain a large supply of different blanks. He must iirst select an appropriate key blank and then, after proper marking of the blank' file a key to fit the tumblers of the lock. The convertible key blank and key 12 Which exemplifies the invention consists of a exibleand deformable casing 36 which is elongated and slender in order to lit into slot 26. The casing has a passage 38 throughout its length. A

part of casing 36 is constricted by sleeve 40 that is slidable on the casing 36 in order to adjust the effective length thereof. The effective length is measured from stop plate 42 to the outer extremity of the casing inside sleeve 40 on the casing 36, the extent of sliding movement being governed by the desired depth of penetration of the key blank into the key slot 26. Although many materials may be adopted for the casing 36, some of the synthetic resinous plastics possess the necessary strength and flexibility, as do some high Igrade rubber compositions. Either is suggested.

A pump 44 which may be manually or power operated has a conduit 46 connected to its outlet, the conduit having a coupling 48 at its outer end. A manually releasable check valve 50 is in the conduit 46 and on one side of the coupling 48. OnA the other side of coupling 48 (Figure l) there is a threaded connector 52- which is secured' to a tube 54. This tube passes through an opening 56 in one end of deformable casing 36 and has a llange 58 which protrudes laterally outwardly at the extremity thereof in order to anchor the tube 54 to the casing 36.

The pump 44 is adapted to deliver a fluent material of a magnetizable nature into the casing 36 under pressure. The iluent material is preferably a supply of iron particles or other paramagnetic matter. To facilitate their owing and to minimize abrasion, the particles of iluent material 60 are in a vehicle of oil, alcohol, air or other duid.

Means to produce an electro-magnetic field in the operative region of the particles are operatively connected with the convertible key blank and key. One suggested devicefor producing this field is shown in Figure 2v and comprises a coil 62 located ou sleeve 40 land having electrical conductors 63 and 64 extending from terminals thereon. These electrical conductors are in a series circuit that includes an electrical potential source 66 and valve 50. This causes the expansible casing 36 to spread andpush the tumbler pins 32 towardand into bores 18. Then by gradually releasing the pressure of the uent material in the casing 36 springs 30 being of equal spring constants or substantially so, and driver pins 28 being of equal length, tumbler pins 32 are returned'into slot 26. This returning movement makes impressions along one'edge 'of casing 36, the depth and configuration of each depression being dependent upon the length of tumbler pins' 32.

Tumbler pins 32 must not be permitted to return too far into the slot 26 inasmuch as they should be stopped in their descent at such time that the upper edge of each are coincident with the wall that forms the bore 20 at the openings to the bores 18. Therefore an electro-magnetic eld is formed around and in the paramagnetic particles by energizing the coil 62. This causes the particles to become a rigid mass thereby rigidifying the casing' the lock is actuated by the convertible blank and key aud after the casing 36 is withdrawn from the lock so that aV permanent, metal key may be made as patterned therefrom.

There are instances wherein certain parts of the casing 36'a1'e best constrained inorder toretain kthe original crossfsectional shape thereof or to. retain a smaller, known cross-sectional shape. In this case the constriction is Y to be restrained from movement while the remainder or other parts thereof are deformed.

Figures 3 and 4 demonstrate a slightly different arrangement of casing 86. Here, the barrel 87 of lock 88 is of the usual construction, having tumbler pins' 89 operable in the kbores 90 of barrel 87 and adapted to be actuated by driver pins (unshown). The keyslot 91 in barrel 87 has the casing 86 located therein', this casing being of identical function and construction to casing 36 it is adapted to be connected to the pump 44 and to have the series circuit of which electrical conductors 63 and 6.4

form aY part connected thereto. .InsteadV of havinglthe A coil62 located on the` exterior of the casing 86, coil is disposed in the casing, the wires 63 and 64 passing throughy anl opening in casing 86 and connecting to terminals on the coil 92. The operation of thisv embodiment of the invention is'identical to the operation of the previously described embodiment 7. However, notethat the* cross-sectional shape of casing 86 is originallyy cir-f cular, prior to the expansion thereof, Whereas the cross-` l sectionalI shape ofthe casing 36 is different. l y Y Figures' 5v and 6 demonstrateA a further embodiment of the invention wherein the casing is made of a'metal j housing' with only one wall 102 beingV deformable. ,In`

this instance the casing 100 is deformable are casings 36 and86, however, the direction of defonnation is restrictedi to'o'ne wall102. The smallhousing 'iscarried' by a tube 104 that is operatively connected'by coupling 48`5to'tlie-s'y'stem disclosed in Figure lfor applying pressureV to the ,wall 102 in the formof a'mass of iluent paramagnetic particles'in a vehicle. Tube 104 is'similar in construction and function to the shank ofI a door loek key and has a longitudinal passage 106 extending tlfn'erethrough.` This passage opens into cavity 108 in' housingf100 so lthat the particles in the vehicle are appliedy into the housing 100 and onto one surface of deformable WallA 102.

with the previous forms of the invention.

The foregoing is considered as illustrative only of the principles' of the invention. Further, since numerous .modifications and changes Will'readily occur to those:-

skilled in the art, it'is not desired to limit the invention' to the exact construction and operation shown and' de'- scribed, and accordingly,all suitable mo'dilcations equivalents maybe resorted to, falling within thev scope of 'the'invention as claimed.

What is claimed as new is as follows:

1. A` key blankconvertible to a key to openaA comprisingan elongated casing having at least onegllexible wall, m'ag'netizable particles in said casing, means for applying pressure to said particles and iu a direction to expand said casing wall with respect to the remainder of the casing While vin the lock, andfrneans to magnetize said particles to form a rigid body therefrom `conforming to the 'shape of the part of said casing in said lock when lsaid part is in the expanded condition.

2. In a key V*blank which may be converted to a key to actuate' alock, the combinationY of a-hollow casing pro+ vided lwith a'llexible part, means operative from the inside of vsaid Vcasing and working in an outward direction' of said'casingfor outwardly moving and deforming said casiri'gdlexible part to conform to the shape of a key, means for retaining said deformed casing in said shape,

and means adjustably mounted on said casing to conaasasrr strain a portion of said iiexible part when said flexible part is deformed.

3. In a key blank which may be converted to a key to actuate a lock, ythe combination of a hollow casing provided with a flexible part, pressure actuated means operative from the inside of said casing and working in a direction outwardly of the casing for outwardly moving and for deforming said casing flexible part to the conflguration of a key, means for temporarily retaining said casing in said configuration, and means connected with said hollow casing to constrain a part of said casing while said casing is being deformed.

4. The combination of claim 3 wherein said pressure actuated means includes a quantity of magnetizable particles in a vehicle.

5. The combination of claim 4 wherein said retaining means comprises a device to produce a magnetic iield in the presence of said particles in order to form a rigid mass therefrom.

`6. The combination of claim 5 wherein said pressure actuated means also include a positive pressure pump, a conductor connected to said pump and in registry with said hollow casing to apply a pressure to the particles and the vehicle.

7. A key blank adapted to tit a number of different size locks and convertible at least temporarily to a key, said blank comprising a casing provided with a passageway and having at least one wall made `ilexible and adapted to Iiit in the key slot of one of the locks, means operative from the inside of said casing and working in an outward direction of the casing for outwardly moving and for deformng at least said wall to assume the shape of a key to tit the lock, said deforming means being tluent material applied into said passageway of said casing under pressure to outwardly deform said exible wall, said fluent material being magnetizable and in a uid Vehicle, and magnetic means to make rigid said wall after being deformed.

8. A key blank adapted to fit a number of different size locks and convertible to a key, said blank comprising a casing provided with a passageway and having at least one wall made flexible and adapted to t in the key slot of one of the locks, means operative from the inside of said casing and working in an outward direction of the casing for outwardly moving and for deforming at least said wall to assume the shape of a key to fit the lock, said deforming means being uent material applied into said passageway of said casing under pressure to outwardly deform said flexible wall, said lluent material having particles which are magnetizable and in a lluid vehicle, a magnetic ield producing means operatively adjacent to said particles, and a control for said lield producing means.

9. A key blank comprising an elongated casing having at least one exible wall, magnetizable particles in said casing, means operative from the inside of said casing and working in an outward direction of the casing for applying pressure to said particles and into said casing to outwardly expand said llexible wall of said casing, and means operatively connected with the particles to magnetize said particles and thereby form a rigid body therefrom.

10. A key blank comprising an elongated flexible casing, magnetizable particles in said casing, means operative from the inside of said casing and working in an outward direction of the casing for applying pressure to said particles and in said casing to outwardly expand said casing to the desired configuration, and means operatively connected with said particles to magnetize said particles and thereby form a rigid body.

References Cited in the le of this patent UNITED STATES PATENTS 2,488,922 Mead Nov. 22, 1949 2,581,489 Kilham Jan. 8, 1952. 2,770,823 Kamborian Nov. 20, 1956 2,802,463 Simjian Aug. 13, 1957 OTHER REFERENCES Steel magazine, July 18, 1949, page 81. 

